Answer by pgee70 for PHP- Get file type by URL

Here is a PHP function I came up with:

/** * @param $image_path * @return string|null */function get_image_mime_type(string $image_path):?string{    $mimes  = [        IMAGETYPE_GIF => "image/gif",        IMAGETYPE_JPEG => "image/jpg",        IMAGETYPE_PNG => "image/png",        IMAGETYPE_SWF => "image/swf",        IMAGETYPE_PSD => "image/psd",        IMAGETYPE_BMP => "image/bmp",        IMAGETYPE_TIFF_II => "image/tiff",        IMAGETYPE_TIFF_MM => "image/tiff",        IMAGETYPE_JPC => "image/jpc",        IMAGETYPE_JP2 => "image/jp2",        IMAGETYPE_JPX => "image/jpx",        IMAGETYPE_JB2 => "image/jb2",        IMAGETYPE_SWC => "image/swc",        IMAGETYPE_IFF => "image/iff",        IMAGETYPE_WBMP => "image/wbmp",        IMAGETYPE_XBM => "image/xbm",        IMAGETYPE_ICO => "image/ico"];    if (($image_type = exif_imagetype($image_path))&& (array_key_exists($image_type ,$mimes)))    {        return $mimes[$image_type];    }    return NULL;}